#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define MAXNM 3005
#define FOR(i, a, b) for(ll i = a; i <= b; i++)
ll n, m, r = 0, dp[MAXNM * 2][3];
char g[MAXNM][MAXNM];
bool ok[MAXNM][MAXNM][2];
vector<array<ll, 2>> e[MAXNM * 2];
int main(){
cin >> n >> m;
FOR(i, 1, n){
string s; cin >> s;
FOR(j, 1, m) g[i][j] = s[j - 1];
}
FOR(i, 1, n){
FOR(j, 1, m){
ok[i][j][0] = (g[i][j - 1] == 'R' && g[i][j] == 'G' && g[i][j + 1] == 'W');
ok[i][j][1] = (g[i - 1][j] == 'R' && g[i][j] == 'G' && g[i + 1][j] == 'W');
e[i + j].push_back({i, j});
}
}
FOR(i, 1, n + m){
ll f = (ll)e[i].size() - 1;
if(e[i].empty()) continue;
dp[0][0] = ok[e[i][0][0]][e[i][0][1]][0];
dp[0][1] = ok[e[i][0][0]][e[i][0][1]][1];
dp[0][2] = 0;
FOR(j, 1, f){
ll x = e[i][j][0], y = e[i][j][1];
dp[j][2] = max({dp[j - 1][0], dp[j - 1][1], dp[j - 1][2]});
dp[j][0] = max(dp[j - 1][0], dp[j - 1][2]) + ok[x][y][0];
dp[j][1] = max(dp[j - 1][1], dp[j - 1][2]) + ok[x][y][1];
}
r += max({dp[f][0], dp[f][1], dp[f][2]});
}
cout << r << endl;
}
